read the content of the file (BINARY)
and insert it in insert \ update MYSQL query
a lot of example in google :
http://www.java2s.com/Code/Java/Database-SQL-JDBC/InsertpicturetoMySQL.htm
http://www.roseindia.net/jdbc/save_image.shtml
http://www.jguru.com/faq/view.jsp?EID=1278882